Hydrogen fuel cells have moved well beyond laboratory demonstrations and niche applications. Stationary power systems are now being contracted at gigawatt scale to serve AI data centers, while heavy-duty trucks and buses are entering commercial deployment across multiple continents. The technology's ability to generate electricity at high efficiency with only water as a byproduct puts it at the center of industrial decarbonization strategies, energy security planning, and the global push to eliminate fossil fuels from hard-to-abate sectors.